plugin_main->callbackObject = (*env)->NewGlobalRef(env, callback);
plugin_main->callbackClass = (jclass)(*env)->NewGlobalRef(env, (*env)->GetObjectClass(env, callback));
// verify API has not changed since jar generation
#define _(N) \
plugin_main->callbackObject = (*env)->NewGlobalRef(env, callback);
plugin_main->callbackClass = (jclass)(*env)->NewGlobalRef(env, (*env)->GetObjectClass(env, callback));
// verify API has not changed since jar generation
#define _(N) \